(a) Field of the Invention
The present invention relates to a thin film transistor array panel for a liquid crystal display, and a method for manufacturing the same.
(b) Description of the Related Art
Generally, a liquid crystal display has two panels having electrodes, and a liquid crystal layer sandwiched between the two panels. Voltages are applied to the electrodes so that the liquid crystal molecules in the liquid crystal layer are re-oriented to thereby control light transmission.
Thin film transistors are formed on one of the panels for switching the voltages applied to the electrodes, and the panel having the thin film transistors is usually called “thin film transistor array panel”. The thin film transistor array panel is generally fabricated through photolithography using masks. One way to reduce production costs is by reducing the number of masks.
Meanwhile, a low resistance material such as aluminum (Al) or aluminum alloy is used for forming wiring lines for the thin film transistor array panel to transmit applied signals with minimal delay. Furthermore, indium tin oxide (ITO) is generally used for forming pixel electrodes for the thin film transistor array panel. However, the ITO has poor contact characteristic with aluminum or aluminum alloy. Therefore, molybdenum or chrome instead of aluminum or aluminum alloy can be interposed between the wiring layer and the ITO-based pixel electrode. However, the manufacturing process is more complicated because the aluminum or aluminum alloy in pad regions must be removed.
Recently, indium zinc oxide (IZO) is proposed for forming the pixel electrodes as well as in forming the pads. However, IZO increases overall contact resistance at contact areas between the respective wiring line components including pads, which deteriorate image display characteristics of the liquid crystal display device. Thus, it is desirable to provide a method of fabricating a thin film transistor array panel for a liquid crystal display which has low resistance material-based wiring lines while ensuring reliability at the contact area.